Attempts have been made previously to attach heating elements to evaporative coolers so that a cold occupied space can be heated, but a difficulty is encountered in that the temperature rise is very small because of the large amount of air which passes over the heating elements, and although the occupied space temperature will gradually increase, the fast moving air in passing over the human body will not give the illusion of warming the body, since it is essentially colder than the body heat and the velocity is a significant factor in cooling of the body. For that reason the previous attempts known to have been made by the applicant have been generally regarded as unsuccessful, and this invention is directed to providing a means whereby a reduced velocity of warmer air can be introduced over a heating element in a device normally used for evaporative cooling.
One of the characteristics of a cooler fan of the axial flow type is that there is much less air flowing from the hub area of the fan than from the outer flow in the annulus which surrounds the hub, and this invention seeks to take advantage of that characteristic.
Thus in one embodiment of this invention a heating element is inserted in the space downstream of a fan of a cooler and in an inner air flow from the hub area of the fan, and there is provided means to obstruct the annulus surrounding the hub area.